Does hill running equate to biking when it comes to pathomechanics ?Think about it, when  you are hill running, one leg is in extension while the lead leg is in more extremes (compared to road running) of hip flexion reaching up the hill for the next step. Isn’t this similar to biking ? On the bike one is bent over leaning forward, the lead leg is in extremes of flexion while the foot on the bottom crank has that same hip in extension.  So does hill running equate to biking ? Well, no. But then it comes to approximating anterior hip structures, there are some similarities. You cannot deny that there seems to be some similarities to pathomechanics.This was a post from a few weeks ago, but this week in our online teleseminar class we went over these principles.  We talked about some of the same biomechanical principles and vulnerabilities in hill running and when in biking.Might be a good time to revisit this brief blog post and see why we had hill running and biking in the same conversation.  Dr. Shawn Allen  Here is the hill running blog post where we mentioned a few things.  http://thegaitguys.tumblr.com/post/143841190479/when-you-run-up-a-hill-most-of-the-cross-over

Does hill running equate to biking when it comes to pathomechanics ?Think about it, when  you are hill running, one leg is in extension while the lead leg is in more extremes (compared to road running) of hip flexion reaching up the hill for the next step. Isn’t this similar to biking ? On the bike one is bent over leaning forward, the lead leg is in extremes of flexion while the foot on the bottom crank has that same hip in extension.  So does hill running equate to biking ? Well, no. But then it comes to approximating anterior hip structures, there are some similarities. You cannot deny that there seems to be some similarities to pathomechanics.This was a post from a few weeks ago, but this week in our online teleseminar class we went over these principles.  We talked about some of the same biomechanical principles and vulnerabilities in hill running and when in biking.Might be a good time to revisit this brief blog post and see why we had hill running and biking in the same conversation.

Dr. Shawn Allen

Here is the hill running blog post where we mentioned a few things.
http://thegaitguys.tumblr.com/post/143841190479/when-you-run-up-a-hill-most-of-the-cross-over

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Abs on the UP, Glutes on the DOWN

I had the opportunity to go on my 1st mountain bike ride of the season last Sunday morning. Yes, I am aware it is JUNE, but the snow has finally melted (we had over 7 FEET at arapahoe Basin in May) and you need to understand that I am usually a runner). In the cool morning 44 degree air I was reminded of the importance of my gluteal muscles (rather than just my quads) while climbing a technical hill which was clearly pushing my aerobic capacity. We have the opportunity to perform many bike fits in the office and treat many cycling ailments. We also train and retraing pedal stroke and one of our mantras (in addition to skill, endurance and strength) is “Glutes on the downstroke; Abs on the upstroke”. Meaning use your glutes to extend the hip from 12 to 6 o’clock and use your abs to initiate the upstroke. Quadricep (on the downtstroke) and hamstring dominance (on the upstroke) is something we see often and this mantra often proves useful in the “retraining process”.

I have been a fan of Ed Burkes work (“Serious Cycling” and “Competitive Cycling”) for years and have read (and lectured about) these books many times. In my effort to find a basis in the literature for my mantra, I ran across a paper (1) that seemed to substantiate, at least in part, the mantra. It is a small study looked at elite athletes that explores changes that occur in muscle recruitment as the body fatigues after a sub maximal exercise session.

Their conclusion “The large increases in activity for gluteus maximus and biceps femoris, which are in accordance with the increase in force production during the propulsive phase, could be considered as instinctive coordination strategies that compensate for potential fatigue and loss of force of the knee extensors (i.e., vastus lateralis and vastus medialis) by a higher moment of the hip extensors.”

This makes sense, although may be contradicted by this study (2), which showed LESS gluteal activity at higher mechanical efficiency, with increased tricep surae activity. They conclude “These findings imply that cycling at 55%-60% V˙O(2max) will maximize the rider’s exposure to high efficient muscle coordination and kinematics.”  Although this study looks at mechanical efficiency and the 1st lloks at muscle activity.

Being seated on a bike and having your torso, as well as hips flexed is not the most mechanically efficient posture for driving the glutes, but clinical observation seems to dictate that the less quad and hamstring dominant people are on the down and up stroke respectively, then the more pain free they are. This does not always equte to being the fastest, but it does equate to fewer injuries showing up in the office.

  1. Dorel S1, Drouet JM, Couturier A, Champoux Y, Hug F. Changes of pedaling technique and muscle coordination during an exhaustive exercise. Med Sci Sports Exerc. 2009 Jun;41(6):1277-86. doi: 10.1249/MSS.0b013e31819825f8.
  2. Blake OM1, Champoux Y, Wakeling JM.  Muscle coordination patterns for efficient cycling. Med Sci Sports Exerc. 2012 May;44(5):926-38. doi: 10.1249/MSS.0b013e3182404d4b.

Welcome to rewind (Late) Friday. Sorry about the late entry, folks.

Along the vein of bike fit, to go with our lecture on onlinece.com this week, here is gentleman with right sided low back pain ONLY when ascending hills on his mountain bike. Can you figure out why?

*Stop, watch the video and think about it before we give you the answer… .

____________________________

This gentleman presented with low back pain, only on his mountain bike, only on long ascents.

He measures out with an 83 cm inseam which should put him on a 44 to 45.5 cm frame (measured via our method). His frame has a dropped top tube and measures 55 cm.

He has a knee bend angle of 20 degrees at bottom dead center. Knee is centered well over pedal axis.

His stem falls far in front of his line of sight with respect to his hub. Stem is a 100 mm stem with a 6 degree rise.

There is a 2" drop from the seat to the top of the handlebars.

He has an anatomically short Left leg (tibial)

Look at the tissue folds at the waist and amount of reach with each leg during the downstroke.

The frame, though he is a big dude (6’+), is too big and his stem is too long. He is stretched out too far over the top tube, causing him to have an even more rounded back (and less access to his glutes; glutes should rule the downstroke and abs the upstroke). This gets worse when he pushes back (on his seat) and settles in for a long uphill. Now throw in a leg length discrepancy and asymmetrical biomechanics.

Our recommendations: smaller frame (not going to happen) lower seat 5-7mm shorter stem (60-75mm) with greater than 15 degree rise lift in Left shoe

We ARE the Gait Guys, and we do bikes too!

BIKE FIT: Case Study

Along the vein of bike fit, to go with Thursday and Friday’s posts last week, here is gentleman with right sided low back pain ONLY when ascending hills on his mountain bike. Can you figure out why?

*Stop, watch the video and think about it before we give you the answer… .

____________________________

This gentleman presented with low back pain, only on his mountain bike, only on long ascents.

He measures out with an 83 cm inseam which should put him on a 44 to 45.5 cm frame (measured via our method). His frame has a dropped top tube and measures 55 cm.

He has a knee bend angle of 20 degrees at bottom dead center. Knee is centered well over pedal axis.

His stem falls far in front of his line of sight with respect to his hub. Stem is a 100 mm stem with a 6 degree rise.

There is a 2" drop from the seat to the top of the handlebars.

He has an anatomically short Left leg (tibial)

Here is some additional video of him with a 3 mm lift in the left shoe. Look at the tissue folds at the waist and amount of reach with each leg during the downstroke in this one as well as the last. no changes were made to the seat height, fore/aft position of seat. or handlebars.

The frame, though he is a big dude (6’+), is too big and his stem is too long. He is stretched out too far over the top tube, causing him to have an even more rounded back (and less access to his glutes; glutes should rule the downstroke and abs the upstroke). This gets worse when he pushes back (on his seat) and settles in for a long uphill. Now throw in a leg length discrepancy and asymmetrical biomechanics.

Our recommendations:

  • smaller frame (not going to happen)
  • lower seat 5-7mm
  • shorter stem (60-75mm) with greater than 15 degree rise
  • lift in Left shoe


We ARE the Gait Guys, and we do bikes too!

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Proper bike fit: Highlights from the Clinic at Summit Chiropractic and Rehabilitation: Part 2

Picking up from yesterdays post, here are some more thoughts.

Saddle/seat fore/aft position: There are two ways to make this measurement:

1) When you’re legs are at 90 degrees in your power stroke (cranks are horizontal), drop a plumb line from the tibial tuberosity (the bump on the leg just below the kneecap, where your quadriceps attaches).  This line should intersect the pedal axis or be slightly behind it.

2) if you like to ride with the seat a little back, drop the plumb line from the front of the kneecap.  It should intersect or fall slightly behind the pedal axis.

The a general rule of thumb is that cyclists in spinning classes, or those who like to push lower gears, tend to sit slightly forward.  Those who push higher gears and spin slower, sit a little further back.

If your seat is too far back it can cause lower back pain because of the increased flexion occurring in the trunk.  Cyclists will often feel pain just below the waist where the gluteal muscles attach or in the middle of the lower back, where the hip flexors attach.  If the seat is too far forward, cyclists usually experience knee pain.

Handlebar Height & Width: Handlebars should be approximately shoulder width and be 0-2 inches below saddle height. The wider they are, the more they open up your chest and allow better breathing, but this is at the expense of aerodynamics. The higher they are, the less stress on your back and neck. With your hands in your most common riding position (on the grips,hoods, or in the drops) you should be able to look down at the center of the stem/handlebar intersection and not be able to see the front axle. If the bar is in front, you may have trouble with descents, if behind, you way be doing wheelies up hill! Problems can often be remedied with a change of stem with a different length, pitch or both.

Handle bar reach: This is the “softest” and factors.  And old standby method used to measure the distance from your elbow to the tip of your middle finger from the tip of your saddle to the center of the handle bar stem.  This measurement will vary, depending upon whether your torso is long or short.  Riding style will also be a determining factor; overall, comfort is the rule.  You may need to buy a shorter for longer stem to make yourself more comfortable.

Bike Fit. The Gait Guys. Yup, we do that too

Bike Fit Clinic Tonite  
 Drs Waerlop and Asthalter (Dr Ivo’s office) will be holding their annual bike fit clinic this evening from 6-7:30 at at Summit Chiropractic & Rehabilitation, PC in Dillon, Colorado. frame sizing, seat height, fore and aft positioning, and handlebar height will be discussed, with common dysfunctions resulting from improper fit. 
 The event is usually a sell out, and we expect nothing less this year. Highlights to follow on the blog!

Bike Fit Clinic Tonite

Drs Waerlop and Asthalter (Dr Ivo’s office) will be holding their annual bike fit clinic this evening from 6-7:30 at at Summit Chiropractic & Rehabilitation, PC in Dillon, Colorado. frame sizing, seat height, fore and aft positioning, and handlebar height will be discussed, with common dysfunctions resulting from improper fit.

The event is usually a sell out, and we expect nothing less this year. Highlights to follow on the blog!